Earlier this week, Devin McCourty was ticking through all the players on both teams that didn’t play in the first Patriots-Broncos matchup.

When he got to the name Sealver Siliga, McCourty threw in an addendum. “He’s been awesome…”

A revelation really. And while we understandably focus on players like Julius Thomas and Jamie Collins whose returns or emergence will be more conspicuous Sunday afternoon, Siliga may be the most impactful change of all.

The well-traveled (San Francisco, Denver, Seattle, New England) 23-year-old defensive tackle has plopped himself down in the middle of the Patriots defensive line and been a bit of an antidote.

Signed to the Patriots practice squad October 23, elevated to the active roster on November 27 – three days after the Broncos ran for 280 yards on the Patriots defense – Siliga has been in the middle of a steadily improving run defense. A run defense that may make it difficult for Denver to replicate their November ground dominance.

Siliga’s now played in six games. Here are the opposing rushing totals in those six games.

Siliga hasn’t accounted for the improvement by himself. The assimilation of Donta Hightower to the inside linebacker spot, some more aggressive defensive playcalling and better secondary tackling have all kept the numbers down. But the fact Siliga has been an upgrade over Isaac Sopoaga and a rotational boon for Chris Jones and Joe Vellano is indisputable.

And this is a kid (one of 11 children, by the way), who nearly packed it in not too long ago. He reflects on the road he’s traveled since coming out of Utah.

“From being on practice squad, to being cut, to being on no team to where I am at today has been pretty big for me,” Siliga acknowledged Wednesday. “To see how everything worked out and to see my hard work paying off is a big (accomplishment).

“There were some times where I wanted to quit,” he acknowledged. “When I got cut by Seattle (October 4, 2013 after yo-yoing from their roster to the practice squad to the street). Being at home, going to workouts, tryouts and getting cut again or not even getting picked up again, going back home. It got pretty hard for me. But family back home, me leaning on their shoulders (allowed me) just to get better (through it), just to keep fighting.

In the league, Siliga’s had plenty of counsel. Former Patriot Ty Warren, a teammate in Denver during Siliga’s long run on the Broncos practice squad, was a big influence.

Sopoaga has been as well. But his family has been the constant.

“My family has been a big help to me,” he said. “I had multiple conversations with my parents (while reflecting on whether to keep playing), multiple conversations with my high school coach back home who had a big impact on my life. There’s been a lot of people back home who’ve helped me.”

And Sunday, the one player who’s drawn a paycheck from each of the teams in the NFL’s Final Four, may have a large say in which AFC team goes.

That’s the beauty of football. The biggest play in Sunday’s game may not come from Tom Brady or Peyton Manning. It may be some guy who seriously thought about quitting just two months ago.

And that’s not even a longshot because Siliga knows what he’s getting into.

“It’s gonna come down to our d-line vs, their o-line,” he predicted. “Whoever plays the most physical game is really gonna make the impact on that game. I should know their o-line because I was over there. It’s not gonna be anything new for me. I practiced against them I’ve done stuff against them. I feel comfortable.”

Tom E. Curran serves as Comcast SportsNet's NFL Insider. Read more from Tom here, or follow him on Twitter or Facebook.